Rechargable battery cells are formed from an anode, a cathode, a separator, and an electrolyte. The anode and cathode react to produce the electric current, with the separator preventing unwanted contact between layers, and the electrolyte allowing the movement of ions between the anode and cathode.
The most common cell geometry for rechargeable battery cells is a wound design. The anode, separator, and cathode are formed into long rectangular strips and placed on top of each other to form an “electrode strip”. They the electrode strip is wound spirally to form an electrode roll, also called a “jelly roll” or “Swiss roll”. A cylindrical cell is achieved naturally, and other prismatic cells can be achieved by flattening the jelly roll, or by wrapping the roll around a shaped core. Terminal tabs are added to the anode and cathode, which protrude from the roll to form the terminals of the cell. The electrolyte is added in liquid or gel form to complete the cell.